Cerny et al., U.S. Pat. No. 5,298,894, discloses a mobile automatic meter reading (AMR) system in which a utility meter transmitter receives signals from a signal transducer insta;;ed on a utility meter and transimits radio frequency (RF) meter data signals to an RF collection unit in a drive-by vehicle. In these mobile AMR systems, a vehicle or a person on foot with an RF collection unit (a walk- by collection system) can move through a neighborhood and collect a large number of readings per hour without entering any of the property of the customers.
Mobile collection units and their associated transmitters have operated in an ISM (Industrial, Scientific and Medical) frequency band around 915 Mhz, since these bands are available nationwide and do not require a license. For these units, transmissions are inly required to reach distances of a few hundred feet, but must be sent out frequently to be available for a drive-by or walk-by collection unit at random times of collection. The unlicensed band is in a narrow range of the radio frequency spectrum, where power associated with the transmission signals is limited to 1 milliwatt, to prevent interference in various areas where the equipment is operating with other RF signals in the enviroment.
Patterson, U.S. Pat. Pub. No. 2005/0225455 discloses a narrow band transmitter with data profiling capability in which the transmitter operates at no more than 1 milliwatt. This was deemed advantageous for operation in a band not requiring FCC licensing and in a transmitter suitable for walk-by and drive-by reception of data from the transmitter.
Data profiling capability is desirable because it collects data at selected usage intervals and provides a record of data usage over many such intervals which provide a data profile to resolve various issues that may arise in the use of the equipment. This function has been carried out by modules separate from the AMR transmitter but located in the vicinity of the AMR transmitter. These are referred to as remote data profiling modules. This function has also been carried out by circuitry incorporated in a transmitter unit and these assemblies are often referred to as “integrated” or “integral” data profiling modules.
Fixed networks, as compared to networks using mobile collection units, transmit signals over distances of more than 1,000 feet and up to distances of one-half mile or more. Fixed network transmitters typically utilize a frequency-hopping, spread-spectrum type of transmission, which by regulation is permitted to use transmitter power up to one (1) watt, which is 1000 times greater than 1 mW limit for narrow band systems.
Today many new home constructions are larger than they were even 10 or 20 years ago. With meters located behind such homes or behind commercial buildings, the automatic reading of these meters with radio equipment is difficult for low power narrow band radios. The use of a higher power transmitter would improve the efficiency of reading of these meters.
It is therefore desirable to provide a higher power transmitter for mobile collection systems that will not be subject to the limitations of the prior art.